Lieberman, B. S.1999Systematic revision of the Olenelloidea (Trilobita, Cambrian)Bulletin of the Peabody Museum of Natural History451-150Fritzolenellus_truemaniMummaspis_occidensMummaspis_truncatooculatusMummaspis_oblisooculatusMummaspis_macerMummaspis_muralensisOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Lieberman_1999af